ScienceDaily (July 18, 2011) — Researchers from Texas A&M University have returned from a trip to examine the scope and size of this year's "dead zone" in the Gulf of Mexico and have measured it currently to be about 3,300 square miles, or roughly the size of Delaware and Rhode Island combined, but some researchers anticipate it becoming much larger.

Oceanography professor Steve DiMarco, one of the country's leading authorities on the dead zone, says the team of researchers journeyed more than 1,400 miles throughout the Gulf over a five-day period, the first ever focusing on the month of June.

DiMarco says the size of the dead zone off coastal Louisiana has been routinely monitored for about 25 years. Previous research has also shown that nitrogen levels in the Gulf related to human activities have tripled over the past 50 years. During the past five years, the dead zone has averaged about 5,800 square miles and has been predicted to exceed 9,400 square miles this year, which would make it one of the largest ever recorded, according to the Louisiana Universities Marine Consortium.

Hypoxia occurs when oxygen levels in seawater drop to dangerously low levels, and severe hypoxia can potentially result in fish kills and harm marine life, thereby creating a "dead zone" of life in that particular area.

Because of record amounts of water flowing from the Mississippi River into the Gulf, there is keen interest in the dead zone areas this year, DiMarco explains, adding that the size of this year's dead zone could still change because large amounts of water are still flowing into the Gulf of Mexico from the Mississippi River.

DiMarco says he will examine the area again on Aug. 8 and will visit many of the same locations for additional data. In all, 10 researchers, including six graduate students, helped to collect data on the latest cruise, which was funded by the NOAA Center for Sponsored Coastal Ocean Research and Texas Sea Grant.